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Abstract Mg₄(TiZnSn)₃, a rare-earth-free Mg-based multi-principal element alloy, was synthesized via high-energy ball milling and cold compaction. Potentiodynamic polarization in 0.1 M NaCl revealed spontaneous passivation with a corrosion current density of 8.96 ± 0.83 µA/cm²and a nobler than Mg corrosion potential of -1058.35 ± 15.91 mV_SCE. X-ray photoelectron spectroscopy confirmed the formation of a mixed oxide film containing ZnO, SnO₂, and TiO₂, contributing to the observed passivity. The alloy also exhibited improved mechanical performance, with a hardness of 5.06 ± 0.41 GPa and Young’s modulus of 109.24 ± 10 GPa. These results demonstrate that tailored multi-element alloying and powder metallurgy can synergistically enhance both corrosion resistance and mechanical properties in Mg alloys. 

Abstract A data set of 23,351 globular clusters (GCs) and ultracompact dwarfs (UCDs) in the Coma cluster of galaxies was built using Hubble Space Telescope Advanced Camera for Surveys data. Based on the standard magnitude cut ofM_V≤ −11, a total of 523 UCD candidates are found within this data set of compact stellar systems (CSS). From a color–magnitude diagram analysis built using this catalog, we find a clear mass–magnitude relation extending marginally into the UCD parameter space. The luminosity function defined by this data set shows an excess of sources at bright magnitudes, suggesting a bimodal formation scenario for UCDs. We estimate the number of UCDs with a different origin than GC to beN_UCD≳ 32 ± 1. We derive the total number of CSS within the core (1 Mpc) of Coma to beN_CSS≈ 69,400 ± 1400. The radial distribution of UCDs in Coma shows that, like GCs, UCDs agglomerate around three giant ellipticals: NGC 4874, NGC 4889, and IC 4051. We find UCDs are more centrally concentrated around these three ellipticals than GCs. IC 4051 has a satellite population of UCDs similar to NGC 4874 and NGC 4889. We estimate only ∼14% of UCDs inhabit the intracluster space (ICUCD) between galaxies in the region, in comparison to ∼24% for GCs (ICGC). We find red (metal-rich) UCDs are more likely located closer to a host galaxy, with blue (metal-poor) UCDs showing a greater dispersion and lower average density in the region. 

To address the challenges of sampling endangered or extinct species in the field, many studies have turned to historically underutilized sources of genetic material: natural history museums. Despite the fact that DNA from specimens collected decades or even hundreds of years ago is often fragmented and degraded, research has shown that historical DNA can still be used effectively to infer phylogenetic relationships and intra-specific patterns of population genetic structure. This synthesis aims to provide students and conservation practitioners with a solid understanding of the methodological strategies needed to apply genetic tools to natural history museum specimens. Specifically, we offer clear definitions and essential considerations for designing a conservation genomics project that includes both modern and historical samples. We recommend that instructors use this synthesis to introduce the foundational knowledge required for two companion exercises: “The Application of Conservation Museomics Approaches to the Protection of the Iberian Lynx (Lynx pardinus)” and “Designing a Conservation Genetics Project Incorporating DNA from Museum Specimens.” 

This exercise is intended to provide students with a real-world example of how museum specimens can provide additional context to challenges and considerations in the broader field of applied conservation genomics. After a brief introduction to the study system—the conservation status of Iberian lynx (Lynx pardinus)—students will be asked to review an open-access, peer-reviewed publication that features samples from varied museum, archaeological, and paleontological contexts. Through reading the guide and discussion questions, students will reflect upon study design, concepts, and challenges presented at the intersection between the fields of conservation genomics and museum-based studies. The exercise ends with students breaking down the research into the main components (e.g., research question, independent and dependent variables, hypotheses, predictions) to set a structure for critically reading other scientific studies or designing their own research question. 

Abstract Plant disease often increases with N, decreases with CO₂, and increases as biodiversity is lost (i.e., the dilution effect). Additionally, all these factors can indirectly alter disease by changing host biomass and hence density-dependent disease transmission. Yet over long periods of time as communities undergo compositional changes, these biomass-mediated pathways might fade, intensify, or even reverse in direction. Using a field experiment that has manipulated N, CO₂, and species richness for over 20 years, we compared severity of a specialist rust fungus (Puccinia andropogonis) on its grass host (Andropogon gerardii) shortly after the experiment began (1999) and twenty years later (2019). Between these two sampling periods, two decades apart, we found that disease severity consistently increased with N and decreased with CO₂. However, the relationship between diversity and disease reversed from a dilution effect in 1999 (more severe disease in monocultures) to an amplification effect in 2019 (more severe disease in mixtures). The best explanation for this reversal centered on host density (i.e., aboveground biomass), which was initially highest in monoculture, but became highest in mixtures two decades later. Thus, the diversity-disease pattern reversed, but disease consistently increased with host biomass. These results highlight the consistency of N and CO₂as drivers of plant disease in the Anthropocene and emphasize the critical role of host biomass—despite potentially variable effects of diversity—for relationships between biodiversity and disease. 

Abstract Rapid-response petrological monitoring is a major advance for volcano observatories, allowing them to build and validate models of plumbing systems that supply eruptions in near-real time. The depth of magma storage has recently been identified as high-priority information for volcanic observatories, yet this information is not currently obtainable via petrological monitoring methods on timescales relevant to eruption response. Fluid inclusion barometry (using micro-thermometry or Raman spectroscopy) is a well-established petrological method to estimate magma storage depths and has been proposed to have potential as a rapid-response monitoring tool, although this has not been formally demonstrated. To address this deficiency, we performed a near-real-time rapid-response simulation for the September 2023 eruption of Kīlauea, Hawaiʻi. We show that Raman-based fluid inclusion barometry can robustly determine reservoir depths within a day of receiving samples—a transformative timescale that has not previously been achieved by petrological methods. Fluid inclusion barometry using micro-thermometric techniques has typically been limited to systems with relatively deep magma storage (>0.4 g/cm3 i.e.  > 7 km) where measurements of CO2 density are easy and accurate because the CO2 fluid homogenizes into the liquid phase. Improvements of the accuracy of Raman spectroscopy measurements of fluids with low CO2 density over the past couple of decades has enabled measurements of fluid inclusions from shallower magmatic systems. However, one caveat of examining shallower systems is that the fraction of H2O in the fluid may be too high to reliably convert CO2 density to pressure. To test the global applicability of rapid response fluid inclusion barometry, we compiled a global melt inclusion dataset (>4000 samples) and calculate the fluid composition at the point of vapor saturation ($${\mathrm{X}}_{{\mathrm{H}}_2\mathrm{O}}$$). We show that fluid inclusions in crystal hosts from mafic compositions (<57 wt. % SiO2)—likely representative of magmas recharging many volcanic systems worldwide—trap fluids with $${\mathrm{X}}_{{\mathrm{H}}_2\mathrm{O}}$$ low enough to make fluid inclusion barometry useful at many of the world’s most active and hazardous mafic volcanic systems (e.g. Iceland, Hawaiʻi, Galápagos Islands, East African Rift, Réunion, Canary Islands, Azores, Cabo Verde).